Automatic speed control of vehicles



Sept. 22, 1931. w. K. HowE 1,824,144'

AUTOMATIC SPEED CONTROL OF VEHICLES' Filed Feb. l0, 1915 2 Sheets-Sheet l Sept.,22, 1931.A

w. K, HQwE AUTOMATIC SPEED CONTROL 0F VEHICLES Filed Feb. 1o, 1915 2 Sheets-Sheet 2 INI/mmf? er l; 57am-Erg W/TNfSSES:

Patented Septu 22, 1931 erstes orifice VI 11??""1-36? EGWE, OF ROCHSTER, NEW' YBK,

stenen coi-PANEL op seres, NEW Yoeri, A conroeerioiv or new voler:

AUToMATic srnnn conosci. yor ventenne Application le. February This invention relates tojiinprovenients in devices for the `sutoinitic` control of the speed from exceeding n seite speed for @ther objects end advantages `Willl appear tue description of the invention4 pro- Liresses, the novelfeeturcs of the. invention will oe particularly pointedoi'it in the p pended cleinis. f

1n describing the invention in detail, reference is hed to the accompanying drawings, vnerein l have illustrated s preferred physicsl embodiment of my y invention, endl wherein like characters o reference designate correspending` parts tiroughout the several views, end in which:

Figure 1 is e. schematic illustration ot e vehicle with epplicents improvements nps plied thereto; Fig. 2, is a schematic dief grani of e i track hsvingepplied thereto the proper errengenient for suitably. c controlling o reiiwsy vehicle movable thereon so that its speed will be suitably autonisticelly controlled.' A-

The vehicle selecled for the purposes of illustration hes been illustrated es supported upon the two reils 1 end 2, constituting a treclrwey. The rails 1 and 2 are supported, as in ordinary practice, by the cross tie 3. The cross tie 3 also supports c third rail 5 designates any suit-able source of elec-` tro-motive force herein illustrated es enel# ternating current generator. The generator 5 is connect-ed. to the primary Winding 61 of e transformer designated generally by 6. rllhe secondary oi" transformer 6 is desig* ne generally by 6?. vOne Aextreme terininel ci tlie secondary Winding 62 is connected oy ineens of the `vire 7 tothe track ruil 2, end the other extreme terminal of the secondary G2 is connected by ineens ot the. Wire 63 to thecontscttcrminel8. Piene locality Where it may be. 1 I

10, 1915. Serial No. 7,287.

tween the extreme termi-nels of the second my 62 ereconnectd et points et successively erithnicticeliy increasing` points ci" potentiel tlievvires 6*', G5, 6, 67 and 6s, Which ere respectively'connected to the Contact terininels c13, 12, 11, 10 and 9. A; switch erin 14 i pivoted et lil end iney by being rotsted upon its pivot be brought successively into Contact Witlthe contact terniinels 13, 12, 11, .1 9 and 8. The pivot point 141 of t itch 14: is conneced cy ineens the rd rail ll. i e "lustrsted, designated l by liei positioned y epplicents genen l, tnercon devices typical orn those conte iplsted L invention vfor suitably 'controlling he speed ofthe vehicle. These devices in the ihain consist of e. conte-,ct device CD; e permissive speed indicator l); s speed indicator S; e warning device YV; end e brake actuating device B.

The Contact device n side bnr 16 which is .supported by the axle 1? of the vehicle C. The Contact device consists oi e vertically niovsole 18 which passes through the projection 19 fastened to the side bei1 1G, o d is spring i essed downwardly by the spring 20, which et one end bears against the projection 19, und et the other end against c coller 21 sstened rigidly to the rod 18. m

CD is positioned on a io prevent the rod 18 frein being forced down so lovv es to cause its upper end to nieve out oi"- tlie projection 19 the rod has beenfenlerged et its upper endlS. 1 y

The zpermissive speed indicator D includes e solenoid 22, one end o which is connected by means ot wire 23 to 'the coller 21 upon the 18, the other end of which is connected by ineens of vrire to any. suitcollsr, 25, posi cned upon erle 17 so is to .ineke goed i; Jsllic Contact therewith. The solenoid 22 hss positioned therein e magnetic core 2G connected by a. link 27 to e spring,` 28, which when the solenoid is deenergized holds the coreA 26 et its upper limit; that nearly Withdrawn freni the solenoid 22 end in the posities shoivn in the drawing.` A lever pivotcd et 29 has one erin 291-extending onone side of the pivot and g raisin.

pivotally connected to the junction between the link 27 and the spring 28; the other arm 292 is located on the other side of the pivot 29 and bears the arcuate metallic member 293. The lever having the arms 291 and 292 is moved together with link v27 and core 26 by thel action of spring 28 to' the position shown in the drawing; that is, resti-ng against the pin 30 when the solenoid 22 is not energized. An energization of solenoid 22 will cause a downward movement f core 26, link 27 and arm 291,- and an upward movement of arm 292 and arcuate metallic member 293, and will thereby cause the arcur ate metallic member 293 to contact successively with contacty springs 31, 32, 33,- 34, 35 and 36, which by means of wires 37, 38, 39, 40, 41 and 42 respectively connect theconmet Sp1-ings 31, 32, 3a,- 34, 35 and 3e with the contact springs 43, 44, 45, 46, 47 and 48.

The aXle 17 has rigidly attached thereto the beveled gear wheel 49, which meshes with the beveled gear wheel 50.y The beveled Vgear wheel 50 is attached rigidly to a vertical shaft 51 supported in bearingsA 521 and 522 of the support 52which is suitably mounted upon the axle 17 so as to' be supported thereby and always maintained at a iiXed relation thereto. The vertical shaft 51 has a collar 511 rigidly attached thereto, and so positioned as to bear upn the top face or the bearing 521, so as to maintain the vertical shaft 51 at the proper height,- so that beveled gear wheel 50 will properly inesh and be turned by beveled gear wheel 49. A double armed lever 53 is pivoted by means of pivot pin 54 to the' vertical shaft v51. This double armed lever 53 has a decided enlargement 531 and 532 at either end thereof so that upon a rotation or vertical shaft 51 and the consequent rotation of double armed lever 53 the effect of 'centrifugal force will be to cause the double armed lever 53 te approach more and more closely a horizontal position. One arin of the double ari'ned lever 53 is connected by means of link 512 to a sleeve 55, which is freely movable longitudinally upon vertical shaft 51. `The sleeve 55 has an enlarged shoulder 551 at its upper end which bears within a groove in collar 56. The rotative movement or sleeve 55 will not cause a rotative movement of collar 56, but a longitudinal movement of sleeve 55 will cause a corresponding longitudinal movement of collar 56. The pin 57rlcated in collar 56 bears within Ia slot in the 'end of arm 581 of a two armed lever pivoted at 58, which has another arm 582 on the oppo; site side or the pivot 58 from the 'arm 581. The arm 582 bears the arcuate metallic member 583, which bearsagainst all of the contact springs 43 to 48 inclusive when in the position as shown in the drawing, and also bears against the stop 59 to klimit a Viuirthe'r rotative movement downward upon its pivot 58. The arcuate metallic member 583 contacts with the contact springs 43 to 48 inclusive when the double armed lever 53 is in the position as shown in the drawing, but upon a rotation of vertical shaft 51 the movement toward the horizontal of double armed lever' 53 causes a downward movement of link 512, sleeve 55, collar 56 and arm 581, thereby causing an upward movement of 582, which causes' the arcuate metallic member 583 to successivelydisengage the contact springs 43 to 4 8 inclusive..

The warning device W may be of any of the well known forms, but has been herein illustrated as an electromagnet 60 having an armature 62 te which a rod 61 is connected that bears at its lower end a piston valve 63, which when Ain the position shown allows air to How freni 'any suitable source of air supply, sueh as' the main reservoir of an air brake system, to a whistle, or similar warning device, 64. The energization of magnet 60 will cause the piston valve 63 to rise and cut off communication between the source of air supply and the whistle 64.

The brake' actuating device B has been herein illustrated as consisting of a solenoid 65 having a core 66, the intermediate portion of whichw is formedlinto a rack 661, and which at its lower end bears the piston valve 662.4 The solenoid 65 when deenergized allows the core 66 to fall and so cause its piston valve 662 to assume the lower position, as shown, thereby allowing air from a train pipe, for instance, to exhaust to atmosphere, thrugh the vents67 and 68, and also around the cre, as at 69; The rack teeth 661 engage with a pinion 70, fastened rigidly to a shaft 71, and the teeth of the gear wheel 70 engage with the teeth of a gear wheel 72, which engage with the4 teeth of a gear wheel 73which by means of any suitable or any well known clutch, as by means of the ordinar'y well known ball clutch, will be connected or dis-connected, according to the direction of rotation otwheel 73, from the shaft 74, rwhich has rigidly attached thereto andA ppsiti'oned at right angles thereto the vane yThe ball clutch between gear wheel 73 andshaft74 is 'so formed that a rigid connection will be formed between the gear wheel and the lshaft 74 when the rack 66 is inoying downwardly, but such connection will not be formed when the rack 66 is moving upwardly, so lthat by virtue of the vane 75, when rack 66 is at its upper limit so that piston valve 662 closes connection between the train pipe and vent 67 and 68,

and desired interval of time may be caused to elapse after a `d'eenergization of solenoid 65 before the piston valve 662 opens connection between the train pipe and the vent 67 and 68. xOn the other hand when rack v66 is is at the lwer limit of its movement it may be picked up instantly by an energization of electromagnet 65..

When all parts are as shown in the drawing there will be no flow of current through electromagnets 60 and 65 and solenoid 22.

li switch arm 14 is moved into contact with contact terminal 13 then a tlow oi current will take place in the Jiiollowing circuit: secondar T 62 wire 7 track rail 2 wheel 7 7 7 76, axle 17, collar 25, wire 24, solenoid 22, wire 23, collar 21, rod 18,`third rail 4, wire 15, pivot 141, switch arm 14, contact terminal 13 and wire 6'l to the terminal ofthe secondary 62. rlhe difference of potential between the terminals of the portion oi secondary 62 included in the above circuit will be assumed to be ten volts. Such difference of potential will cause such a flow o current through solenoid 22 as will cause itto move core 26 downwardly a sui'licient distance to cause link 27 through arm 291 and arm 292 to move arcuate metallic member 293 into contact with contact spring 31. VTUnder such conditions a circuit will be formed as follows: Positive terminal ot battery 77, wire 78, arm 292, arcuate metallic member 293, Contact spring` 31, wire 37, contact spring arcuate metallic member 583, arm 582, wire 79', electromagnet 60, wire 80, solenoid 65 and wire 81 to the other terminal or the battery 7T. Current flowing in the above traced path will energize electromagnet 60 and so shut oil connection between the main reservoir and the whistle 64, and so cause the whistle to cease sounding. The current will also sufficiently energize solenoid 65 to cause core 66 to be drawn to its upper limit, thereby closing the path from train pipe to atmosphere.

It the vehicle should now move and attain a certain predetermined low speed as for instance live miles per hour, then the arcuate metallic member 583 would be moved upwardly so as to break contact with oo ntact spring 43, which would break the circuit through elcctromagnet 60 and solenoid 65 hereinbetore traced. The breaking of such circuit would immediately cause the warning whistle 64 to sound and would also allow core 66 to move downwardly, but by virtue of the time interval mechanism connected to core 66 it would not descend so rapidly that it would vent the train pipe to atmosphere before the driver of the vehicle had an opportunity to suliiciently reduce the speed of the Vehicle so that arcuate metallic member 583 would move back into contact with contact spring 43. As soon as contact was again made between arcuate metallic member 583 and contact spring 43 the circuit hereinbetore traced through which current flowed to energize electromagnet 6() and solenoid 65, would be again formed and the warning whistle 64 would be silenced and the connection between the train pipe and atmosphere would not be formed. If switch arm 14 were placed in contact with contact terminal 12 then such a section ot the secondary 62 of the transformer 6 would be placed in the circuit with solenoid 22 as would cause a current to flow by virtue of a difference of potential greater, as for eX- ample, twice as great as when the switch arm was in contact with contact terminal 13. Under such conditions core 26 would be drawn down so Jfar as to cause arcuate metallic member 293 to contact not only with contact spring 31, but also with contact spring 32, so that the speed of the vehicle could then be increased to the point where. arcuate metallic member 583 just tailed to break contact with contact spring 44. If switch arm 14 were placed in contact with contact terminal 11 then the available difference oi potential would be three times what it was when the switch arm was in contact with contact terminal 13, and arcuate metallic member 293 would move into contact with contact spring 33 so that the speed of the vehicle could then be increased to a point where arcuate metallic member 583 just failed to break contact with contact spring 45. It switch arm 14 were placed in contact with contact terminal 10 then arcuate metallic member 293 would move into contact with contact spring 34 and the speed j of the vehicle could be increased to the point where arcuate metallic member 583 just failed to break contact with contact spring 46. It switch arm 14 were placed in contact with contact terminal 9, then arcuate metallic member 293 would be moved into contact with contact spring 35 and the speed of the vehicle could be increased to a point where arcuate metallic member 583 just failed to break contact with contact spring 47. It switch arm 14 were moved into contact with contact terminal 8, then arcuate metallic member 293 would be moved to the limitJ of its motion, as indicated by dotted lines, and would make contact with contact spring 36 and with all of the other contact springs, and the speed of the vehicle could be increased to a point such that arcuate metallic member 583 just Jtailed to break contact with contact spring 48.

lWith arcuate metallic member 293 making contact with all of contact springs 31 to 36 inclusive, the speed ot 'the vehicle can reach its highest possible value, but even witharcuatc metallic member 293 in the position as described the speed of the vehicle is not un limited, for if it increases to such a point that arcuate metallic member 588 breaks contactwith Contact spring 48, ther, in the manner hereinbefore described electromagnet 60 will be deenergized, sounding the warning whistle and solenoid 65 will be deenergized, causing a venting of the train pipe, but just as hereinbefore described, if

iis

the circuit is actually broken under such conditions by the movement of arcuate metallic member 583,1"rom in contact with contact spring 48 when moving upwardly, then` a proper interval of time will `elapse between the sounding of the whistle 64 and the actual venting ot the train pipe sutc-ient to allow the driver of the vehicle to take control of the vehicle and reduce its speed so that arcuateV metallic member 583 would again contact with Contact spring 18 and again close the circuit through the electromagnet and the solenoid 65, so as to stop the warning whistle and close the vent from the train pipe to atmosphere.

N ot onlT7 will the circuit through electroi iagnet 60 and solenoid 65 be broken by an excessive speed, but it the speed is not excessive, but is just ot suiiicient value to maintain the arcuate metallic member 583 to the dotted line position shown in Fig. 1, so that is is in contact with contact spring 18, the circuit may also be broken by moving switch arm 1e from in contact with contact terminal 8 to in contact with contact terminal 9, which will cause the arcuate metallic member 293 to drop back trom in contact with contact spring 36, which will break the circuit through electromagnet 60 and solenoid 65 and result in giving the warning and venting the train pipe. It the switch arm 111 is noved into contact with contact terminal 9, then the driver must reduce the speed or" the train suliciently to allow arcuate metal ic member 583 to drop back sufficiently to make Contact with contact spring` 417. Then it the switch arm 14.- is moved into contact with contact terminal 10 the arcuate metallic nember will drop back out o1 contact with contact spring and then the speed of the train must be reduced sufficiently to cause arcuate metallic member 583 to move back suiiiciently to make contact with contact spring 46, and so on until switch arm 14 is moved into Contact with contact terminal 13, which time the arcuate metallic member 583, as hereinbefore explained, must make contact with Contact spring 43, or the warning will be sounded and the train pipe vented.

Froii the above description it will be seen that the control ot trie train is governed by two factors: One,` the permissive speed established or determined by the value ot the electro-motive force causing a dow of current through solenoid 22; the other, the actual speed of the train. The value of the actual speed tac-tor must never be excessive for the value of the permissive speed Jfactor established by the electro-motive torce existing. lt it does automatic application of the brakes is eiiected if the driver of the vehicle does no take immediate notice of the preliminary warning and lower the value of the actual speed factor so that it will not be excessive compared with the permissive speed factor existing at that time.

To make use of the arrangement shown in Fig. 1, as positioned on the movable vehicle in an automatic system upon an actual railway, it is merely necessary to re-produce automatically they varying dilierences of potential which were created manually by the movement of switch arm 14 described in connection with Fig. 1. This applicant has done, and by reference to Fig. 2 will be seen a preferred ari-angel Lent.

In Fig. 2, 1 designates one rail ot a railway track, of which 2 designates the other rail and l designates the third rail. The track is divided by insulating joints 88 into electrically isolated sections, and the third rail l is divided by the insulating joints 89 in the same manner into electrically isolated sections. Each of the electrically isolated sections or" the track rails 1 and 2 have connected across them at one end a source of electro-motive torce, as 90, and at the other end translating device in the form of a relay, as 91, 92, 93, 9e, 95, 96, 97, 98 and 99. Each of the relays 91 to 99 inclusive control armatures which are in the upper position vlien no train is upon the track section to ich the relay is connected, but which are in the lower position when a train is upon the track section to which the relay is conrrny suia le source ot electro-motive orce, herein shown as alternating cu rent jenerator, and designated 5, may be emloyed to which are connected the line wires 00 and 101 which extend the length oi the trackway. At suitable points in the primaries 1021, 1031, 1011, 1051, 1081, 1071, 1081 and 1091 of the transformers 102, 108, 10a, 105, 106', 107, 108 and 109 respectively are connected across the line wires 100 and 101. The secondaries of the transformers 102 to 109 inclusive are each formed in the same manner as the secondary 62 shown in Fig. 1; that is, one terminal of the secondary is connected directly to track rail 2 and the other extreme terminal is connected to the liront point ci a track relay. The intermediate taps on the transformer are connected to the back point-s of a track relay. rlhis will be evident by referring to the secondary oi transformer 102 where it will be seen that one extreme terminal of the secondary is connected by means of wire 110 to the track rail 2; the other extreme terminal is connected by means of 1023, to a front point ot relay 91, which co-acts with armature The tirsb and lowest voltage step is between v-.f'ires 110 and 102* and wire 102'1 is connected to a back point co-acting with t he next voltage step is bearmature 911. tween wire 110 and wire 1025 and wire 1025 connects with a back point which co-acts with armature 912. The next voltage step is between wire 110 and wire 1026 and wire 1026 connects with a back point which coacts with armature 913. The next voltage step is between wires 110 and 1027 andwire 1027 connects to a back point co-acting with armature 911. The next voltage step is between wires 110 and 1022 and the wire 1028 is connected to a back point co-acting with armature 915.

Each of the transformers 102 to 109 inclusive have secondaries formed as shown in the ligure in exactly the same manner, and aro connected in exactly the same manner, to the respective relays 91 to 99 inclusive, although, ot' course, it is to be understood that the particular arrangement shown is merely illustrative, and that in practice the connections and arrangements would be such as would be dictated by good signalling practice on account of the exigencies of the particular section of traclway to which the system would be applied.

i car or train is shown upon the trackway and designated C. lilith a train on the traekway at such point different differences or" potential would be created between the track rail 2 and the successive sections of third rail 4 back of the train C, until a point was reached behind which all sections of the track rail 4 would be at equal differences of potential with the track rail 2.

The train C being on the section indicated would cause a deenergization of relay 97, thereby causing all of its armatures 971, 972, 97 3, 974 and 975 to be in the lower position, as shown. Under such conditions the section f of thivd rail 4 connects by means of wire 110 with armature 971, and so with tap 1084, which is the lowest voltage tap, so that the lowest diiiierence of potential would exist between the track rail 2 and the section f, consequently, any train upon the trackway opposite the section f, if equipped with the arrangement shown in Fig. 1, would necessarily have to be movingat a speed, say, not greater than tive miles an hour, or the warning whistle would be sounded and the train pipe vented. The third rail section e would connect by means of wire 111 with armature 961 in the upper position as shown, contacting with wire 112 which at its other end would connect with armature 97 2 in the lower position as shown, and would connect section e with the second tap on the transformer 1085, and consequently a train upon the trackway opposite section ye could not be r wing at a speed greater than, say, ten miles per hour. Section d would connect by wire 113 with relay armature 951, which would be in the upper position as shown, contacting with wire 114, which at its other end connects with armature 962, which would be in the upper position, as shown, connecting with wire 115, which at its other end connects with armature 97 2', which would be in the lower position, as shown, thus connecting section d with tap 1086, so that a train upon the trackway opposite section d could not be moving at a speed greater than, say, twenty miles per hour. Section c would be connected by means of wire 116 to armature 941, which would be in the upper position, as shown, connecting with wire 117, which connects at its other end with armature 952, which would be in the upper position as shown, connecting with wire 118, which at its other end connects with armature 963, which would be in the upper position, as shown, connecting with wire 119, which connects with armature 974, which would be in the lower position, as shown, thereby connecting with tap 1087; consequently, any train upon the traclrway opposite the section c could not be moving at a speed greater than, say, thirty miles per hour. Section b would be connected by wire 120 with armature 931, which would be in the upper position, as shown, connecting with wire 121, which at its other end connects to armature 942, which would be in the upper position, as shown, connecting with wire 122, which would connect with armature 953, which would be in the upper position, as shown, connecting with wire 123, which at its other end connects with armature 96, which would be in the upper position, as shown, connecting with wire 124, which at its other end connects with armature 975 in the lower position, as shown, thus with tap 1088, so that any train upon the trackway opposite the section Y) could not be moving at a speed greater than, say, forty miles per hour. Section a would be connected by wire 125 with armature 921, which would be in the upper position, as shown, connecting with wire 126, which at its other end connects with armature 932, which would be in the upper position, as shown, connecting with wire 127, which at its other end would connect with armature 942, which would be in the upper position, as shown, connecting with wire 128, which at its other end connects with armature 954, which would be in the upper position, as shown, connecting with wire 129, which at its otherend would be connected with armature 965, which would be in the upper position, as shown, connecting with tap 1073, so that section w would thereby be connected with tap 1073 and the full potential of the secondary of transformer 107 would exist between the section a and track rail 2, so that a train upon the trackway opposite that section could move at a speed limited only by the position of the arcuate metallic member 583; that is, it could move at the highest permissible speed allowed upon the railway. All of the sections of the third rail 4 located back of section a would with train C located as shown in Fig. 2 be connected with the eX- treme terminal of the secondary of a transformer; that is, section al, tor instance, would be connected by means oi' wire 130 to armature 911, which would be in the upper position as shown, connecting with wire 131, which its other endlwould be connected with armature 922, which would be in the upper position as shown, connecting with wire 132, which at its oth r end would be connected with armature 933, which would be in the upper position as shown, connecting with wire 183, which at its other eno would be connected with armature 941, which would be in the upper position as shown, connecting with wire 13e, which at its other end would be connected to armature 955, which would be in the upper position as shown, connecting with wire 1063, so that the full potential of the secondary of transformer 106 would exist between the third rail section al and the track rail 2.

The insulating joints 89 are placed just far Venough back insulating joints 88, so that the contacting device as i8 ot a train will contact with another section oi third rail before the difference ot potential between the section with which it has been in contact and a rail ot the track has been reduced to the lowest value so that excessive abrupt changes in diilerences ot potential between a third rail and the track rail will not be encountered by the contacting device on the vehicle.

From the above description it will be seen that a train equipped as shown in Fig. l, moving upon a section ot' trackway equipped as shown in 2, would be able to move at the highest permissible speed just so long as itwas on a section ottrackway opposite a third rail section between which and one of the track rails the highest difference of potential existed, but that as a train approached a preceding vehicle upon the trackway the driver of the vehicle would be obliged to make successive reductions in speed until he reached the section of trackway just in the rear of the precedingtrain, at which place the speed of the vehicle would be not above such a speed as would enable him to bring the vehicle to a stop in a ver f short distance. Y

The speed at which vehicle would be allowed to move in a system such as has been hereinbeore described would be a speed not above the speed at which a train could be automatically stopped or brought down to a non-dangerous speed before reaching a preceding' tra that is, the vehicle would be allowed to travel .t that rate of speed consistent with the greatest capacity ot the road and proper safety. Furthermore, no automatic application ot brakes would occur just so long as the driver of the vehicle controlled the vehicle in accordance with the indications given.

Although applicant has herein described his invention as applied to a straight section of trackway uniformly connected and arranged throughout, is not to be understood that in practice applicant is limited to that precise arrangement, because, as is well known to those skilled in the art of railway signalling, the speed at vhich vehicles may move upon ditl'erent sections oli f1 given tracki'ay is governed not only by the presence oiE movable hazards ahead, such as preceding vehicles, but also by the existence oit fied hazards such as curves, grades, station stops and switches, so that in practice the system actually used would only in rare cases exhibit the uniformity illustrated by applicant in the drawings, but would be arranged so that proper speeds ot the vehicles coull be maintained, having` due regard not only to preceding vehicles, but to the lined hazards along the right ot way. Such manges, however, are well within the skill oi' the signal engineer, and could be et- 'ected without departing from the principle or spirit of the invention.

Also, while the particular embodiment of the invent-ion shown and described establishes communication between the trackway and the moving vehicle by means oi contact rail sections along the track cooperating with a contact shoe carried by the vehicle, the invention is not limited to this particular means oi" transmitting impulses to the vehicle, and l desire to have it understood that other forms et impulse transmitting means capable of. performing the functions and producing the action desired, may be used without departing from my invention.

Although l have particularly described the construction of one physical embodiment et my invention, and explained the operation and principle thereof; nevertheless, I desire to have it understood that the form selected is merely illustrative, but does not exhaust the possible physic l embodiments of the idea of means underlying my invention.

That I claim as new and desire to secure by Let-ters Patent of the United States, is:

1. In a system of automatic train control for protecting railway trailic, in combination: a railroad track; impulse transmitting devices distributed along the track; means responsive to the presence ot' a train en said track for producing progressively varying electrical conditions ot' several oi said impulse transmitting devices in the rear of said train; and means on a follow f' vehicle responsive to said varying electrical conditions of said impulse transmitting devices for automatically enforcing corresponding limitations on the speed of said following vehicle. f

2. In a system for protecting railway trailic, in combination: a track divided into l l o units a plurality of which constitute braking distance; train controlling means associated with each unit, means whereby a train produces diflerent electrical conditions in said train controlling means in the rear of that train; said electrical condition of each unit being regulated by said means in accordance with the di tance between that unit and the rear of said train; and means on a following train responsive to the electrical conditions of said train controlling means at substantially all points in the travel of the train over each unit for regulating the speed of said following train in accordance with its distance from the preceding train.

3. In a system of automatic train control for protecting railway tratiic; in combination: a railroad track divided into sections provided with normally closed 'track circuits, a plurality of which constitute braking distance for the vehicles traveling on the track; impulse transmitting devices associated with said track sections and impressed with progressively varying electrical conditions according to the number of said .ilurality of track sections in advance thereof that not occupied; and means on a following vehicle for automatically enforcing limitations upon its speed in accordance with the variations in the electrical conditions of said impulse transmitting devices.

el. In a system of automatic train control for protecting railway traflic, in combination: a railroad track; impulse devices disposed along said track; means responsive to the presence of a train on said track for producing progressively varying controlling` conditions or said impulse devices in the rear thereof in accordance with the distance between these respective devices and said train; and automatic means on a following vehicle controlled electrically by said devices for imposing a different lixed speed limit for each different controlling condition of sait. impulse devices,

In a system for protecting railway traffic; in combination: a track; a vehicle adapted to travel on said track; means responsive to alternating currents of (ililierent characteristics for governing the speed of said veiicle; and means for supplying such alternating currents to said means at substantially all points along the track; aid last mentioned means varyiir;` the elec "rical characteristics of said currents progressively in accorc ce with the extent of unoccupied track in advance of the vehicle.

G. In a system of autoniatic'train control for protecting` railway trar'lic; in combination: a railway vehicle and a tra-ck therefor; impulse means adapted to conmunicate different controlling impulses to the vehicle at intervals along the track; means on the vehicle responding to the actual speed thereof; means on the vehicle adapted to be influenced to a variable degree by said impulse means for establishing correspondingly varying permissive speeds for the vehicle; a warning signal governs by both of said means and operated when the actual speed of the vehicle exceeds its permissive speed; a slow-acting device adapted to assume its ultimate condition after an interval of delay following its initial operation, said slou -acting device being also governed by both of said first mentioned means; and a brake-setting appliance actuated by said slow-acting means after it has assumed its ultimate condition.

7. In a system for protecting railway traffic; in combination: a track divided into track circuit sections; a Contact rail associated with each track section and adapted to transmit controlling impulses to a vehicle passing through the Correspendingtrack section; and means governed by said track circuit sections for establishing a difference of potential between each Contact rail and a track rail which varies in intensity according to the number of unoccupied track sections in a portion of the track in advance of the corresponding track section.

S. In a system for protecting railway traffic, in combination: a track; a vehicle adapted to travel upon said track; means on the vehicle for establishing a permissive speed therefor; traliic controlling devices located along the track and adapted to govern said means on the vehicle; and means for varying the electrical conditions of said controlling devices to thereby establish difierent permissive speeds for said vehicle.

9. In a system for protecting railway traiiic, in combination: a track divided into track circuit sections; a vehicle adapted 'to travel over said track; a contact rail associated with each track section and extending the length thereof; means controlled by said track circuit sections for establishing a difference of potential between each contact rail and a track rail varying in electrical characteristics.according to the number of several track sections in a portion of said track in advance of the corresponding track section which are not occupied; trailic protecting means on the vehicle responsive to currents of different characteristics; and means for establishing electrical communication between said contact rails and. said last mentioned means. l

l0. In a system for protecting railway traflic, in combination: a track divided into track circuit sections; a vehicle adapted to travel on said track; a contact rail associated with each track section; means controlled by said track circuit sections for establishing a difference of potential between each Contact rail and a track rail which varies.

in intensity according to the number of unoccupied track sections in a. portion of said track in advance of the track section corresponding to said contact rail; a shoe carried by the vehicle and adapted to coopera-te with said contact rails; al partial circuit on the vehicle terminating at said shoe and at the wheels of said vehicle; means controlledby said partial circuit for establishing the permissive speed of the vehicle; means responding to the actual speed of the vehicle; and means for governing the movement of said vehicle governed by the co-action of said two last mentioned means and operated when the actual speed of the vehicle exceeds its permissive speed.

11. In combination, a. railway vehicle, a vehicle controlling means thereon, means for controlling said vehicle controlling means comrrising a speed governor controlled part and a speed limit device, said speed limit device including an electricallyoperated translating device having a movable part whose movement is proportional to the strength of current passing therethrough, and electrical means along the trackway co-operating with said translating device to cause currents of different current strengths to pass therethrough.

12. In combination, a railway vehicle, vehicle controlling means thereon, mea-ns for controlling said vehicle 'controlling means comprising a speed-controlled part and a speed limit device operable in accordance with the strength of current passing therethrough, and electrical means along the trackway co-operatin g with said speed limit device to cause currents of different current strengths to pass through said speed limit device.

13. In a system for protecting traffic on railroads having a track divided into units, the combination with a stationary impulse transmitting device associated with each unit and adapted to be controlled electrically to assume any one of a plurality of different controlling conditions, of means associated with each unit for detecting the presence of a train thereon, trackway apparatus and circuits controlled by each of said means for cansino' a plurality of said impulse transmitting devices in the rear thereof to assume controlling conditions which vary in accordance with the distance between each particular device and the unit occupied by a train, and automatic apparatus on a following vehicle responding to the varying controlling conditions of said impulse transmitting devices for automatically enforcing corresponding limitations on the speed of the following vehicle, whereby the speed of the following vehicle regulated in accordance with the distance between it and the forward train.

14. ln a system for protecting traffic on railroads having tracks divided into track circuit sections, the combination with a stationary impulse transmitting device associated with each track section and adapted to assume any one of a plurality of controlling conditions, each impulse transmitting device being controlled electrically by the track circuits of a plurality of track sections in advance thereof and being caused to assume a particular controlling condition corresponding to the number of these track sections in advance which are not occupied, and automatic apparatus on a following vehicle for restricting the speed thereof to a different fixed speed limit for each controlling condition of said impulse transmitting devices, whereby a gradually decreasing limitation on the speed of the following vehicle is automatically enforced as it approaches a train ahead.

15. ln a system for protecting traflic on railroad tracks, the combination with stationary impulse transmitting devices distributed along the track, each adapted to assume any one of more than three different controlling conditions, of means associated with each of several predetermined portions of the track and responsive to the presence of a train on the corresponding portion for governing the controlling condition of a number of impulse transmitting devices in the rear thereof in accordance with the distance between each particular device and said occupied portion of track, and means on a following vehicle responsive jointly to its speed and the varying controlling conditions of said impulse transmitting devices for automatically controlling the movement of the following vehicle.

16. ln a system for protecting railway traffic; a track divided into track circuit sections; a Contact rail extending along the track and divided into sections corresponding to each track section; and means governed by said track circuit sections for establishing a difference of potential between each contact rail section and a track rail which varies in intensity according to the number of unoccupied blocks in a portion of the track in advance of the corresponding track section.

17. In a system for protecting traflic on railroad tracks, the combination with several impulse transmittingmeans distributed along the track and adapted to assume progressively varying distinctive controlling conditions throughout a region of limited extent, of trackway apparatus and circuits responsive to the presence of a train on the track for governing the controlling condition of said means, and automatic apparatus on a following vehicle responding selectively to the distinctive controlling conditions of said means at substantially all points in the travel of the vehicle and acting to automatically enforce a limitation on the speed region, of automatic means on a vehicle responding to the influence of said impulse .transmitting devices at substantially all points in its travel for automatically enforcing correspondingly varying limitations on the speed of said vehicle.

26. In a system for automatically protecting` trafiic on railroad tracks, the combination with a plurality of stationary impulse transmitting devices distributed along the track and adapted to have yirogressively varying controlling chara-cteristics. of automatic mechanism on a vehicle responsive to the influence of said impulse transmitting devices at substantially all points in the travel of the vehicle and acting under such influence to prevent the vehicle at each device exceeding a predetermined speed prescribed by that particular device, and track- Way apparatus responding to the presence-oil a train on the track for causing the impulse transmitting devices throughout a region oi .limited extent behind such train to assume contr lling characteristics which have a progressively varying influence on the mechanism on following vehicle as it travels through this region, whereby gradually decreasing restriction on the speed of the following vehicle is established said following vehicle approaches the train ahead.

27. In a system for automatically protecting traffic on railroad tracks, the combination With impulse transmitting means for communicating controlling impulses of varying influences from the track to a vehicle traveling on the track, said impulse transmitting means comprising elements on the vehicle cooperatingv With stationary elements distributed along the'track, of means controlled by the presence of a temporary hazard along the track for supplying to the trackway elements of said impulse transmitting means electrical energy Which varies `progressively according to the location of the particular trackvvay element relative to the hazard, automatic controlling. mechanism on the vehicle comprising a speed responsive device governed by the actual speed of the vehicle and a permissive speed device susceptible to said controlling impulses, and means governed jointly by said speed responsive device and said permissive speed device for retarding the movement oit the vehicle Whenever its actual speed exceeds the prescribed permissive speed.

28. In a system for automatically protecting traffic on railroad tracks, the combination with automatic mechanism for controlling the movement of a vehicle comprising a speed responsive device having its controlling condition governed by the actual speed of the vehicle, ot a permissive speed device capable of having its controlling condition regulated by the varying intensity ot' electrical energy supplied thereto, and means governed `jointly by said speed responsive device and said permissive speed device for retarding the movement of the vehicle Whenever its actual speed exceeds the prescribed permissive speed.

29.k In a system for automatically protecting trailic on railroad tracks, the combination with automatic mechanism on a vehicle including a permissive speed device adapted to he influenced by the varying intensity of electrical energy supplied thereto and acting to establish different permissive speeds for the vehicle, of impulse transmitting means including elements distributed along the track and adapted to cooperate With an element on the vehicle for controlling the intensity of the electrical energy supplied to the permissive speed device iii-accordance with the presence and location-ot a temporary hazard along the track.

30. In a system for automatically protecting ti tion with a permissive speed device on a vehicle adapted to establish threeor more different permissive speeds for the vehicle byassuming diil'erent conditions, of means ailic on railroad tracks, the combina-v tor automatically retarding the movementy of the vehicle when such established permissive speed is exceeded, and trackway apparatus including stationary impulse elements located at intervals along the track and adapted to act under the influence ofA the presence oic a train on the track to cause said permissive speed device to assume its different conditions at substantially Yall points in the travel of the yvehicle in accordance with the' relative location oi" the vehicle and the train ahead.

31. In a system ior automatically protecting-traiiic on railroad tracks, the combination With impulse transmitting means including stationary elements distributed along the track and adapted to change from normal controlling condition to any onc of several other controlling conditions, of means responsive to the presence of a train on the track for causing said elements ing train to a predetermined speed at each element corresponding to the existing controlling condition of that element.

32. In a system for protecting tra'lic on railroad tracks, the combination with automatic apparatus on a vehicle responding to the actual speed of the vehicle, ot means partly on the vehicle and partly along the track for establishing a permissive speed for the vehicle in accordance with tho eX- tent ot unoccupied track in advance thereof, a warning signal governed jointly by said apparatus and said means and operated When the actual speed otl the vehicle exceeds` its prescribed permissive speed, and brake controlling means on the vehicle also governed jointly'by said apparatus and said means and operated after an interval ot delay Jfollowing` the operation of said Warning signal.

ln a system for automatically protecting trailic on railroad tracks, the combination With a movable member on a vehicle havingl its position determined by the controlling condition or" devices distributed along the track, ot a second movable meinber having its posit-ion determined by the actual speed oi" the vehicle, a Warning signal, brake controlling mechanism for the vehicle acting to apply the brakes ot the vehicle after an interval of delay following its initial operation, and means controlled jointly by said movable members for iiperaling the Warning signal and said brake controlling mechanism simultaneously.

ln a system tor automatically protecting traflic on railroad tracks, the co `ibination with a vehicle, ot automatic brake control apparatus on the vehicle acting to apply the brakes after an `interval ot delay following its initial operation, a Warning signal on the vehicle arranged to give an arrestive indication to the operator oit 'the vehicle, and means on the vehicle cooperating ivili means along the track for causing simultaneous operation ot said Warning signa and said brake control apparatus Whenever the vehicle exceeds certain prescribed limiting speeds at control points along the track.

35. In a system for'automatically protecting traffic on railroad tracks, the combination with trackvfay apparatus comprising a plurality oit inlluence elements distributed along the track, of automatic mechanism on the vehicle responding to the influence oi said elements for restricting the speed of the vehicle at each element to accord with 'the permissive speed prescribed by that element as a result of its controlling eilect on said mechanism, said mechanism having a tendency to impose the lowest 'speed restriction, said elements a ng to exert influence in opposition to s. ble ot'liavinfi 'for imposing variable restrictions on the speed thereof, said mechanism having a tendency to impose the lowest speed restriction, et normally closed track circuit, and means controlled by said track circuit for eX- -erting` an influence on said mechanismv in opposition to said tendency to a variable degree at substantially all points in he travel ot the vehicle and causing said mechanism to n `impose diterent hired speed restrictions varying step by step substantially in accordance Wit-h the location ot 'the vehicle relatively to said track circuit.

3'?. ln a system for automatically protect ing traliic on railroad tracks, the combina tion with a changeable element on a vehicle having a tendency to assume an onreine condition, ol automatic means on the vehicle controlled by said element tor imposing A varving restrictions on the speed ot the vel liicie, the restricted speeds for the vehicle established by said means being progressively decreased by predetermined increments of speed as said element changesoivard itsV eXtrem-e condition, and automatic means including trackway elements responsive to the presence of a train on the track for causing said element to change progressively tovvartl its extreme condition at successive points said trackway elealong` the track Where ments are located.

38. In an automatic train cont-rol system, the combination With a vehicle, of a Warning signal on the vehicle adapted to givean arrest-ive indication to the operator therenormally closed circuit for'siniultaneously causing operation of said Warning signal and said slow-acting device at control points along thetrack under dangerous tratlic conditions.

j 39. ln an automatic train control system, the combination with automatic train control apparatus for a railway vehicle including a Warning signal, a slee -acting device, a brake-setting appliance actuated by said slow-acting device when it has attained its ultimate condition; ot means comprising elementspsrtly on the vehicle and partly at cont ol points along the track forcausing simultaneous operation of said Warning signal and said sloiv acting device, said means bei g elifective when the vehicle exceeds predetermined limiting Speeds in passing said control points, the trackivay elements of said means beine' responsive to the presence ot another train ahead. f

Ll). In :an automatic train control system,

ioo

the combination vwith automatic train controluapparatus for railway vehicles including a warning signal, a time controlled device, and a brake-setting appliance operated by said time-controlled device after the lapse of a predetermined time; of impulse transmitting vmeans comprising elements partly on the vehicle and partly along the track for causing simultaneous operation oi' said warning signal and said time controlled device; and means responsive to the presence ci another train. ahead for determining the controlling condition of the trackway elements of said impulse transmitting means in accordance with traific conditions ahead.

4l. In an automatic train control system, the combination with a vehicle, el: an electrically controlled warning signal, an electrically governed time controlled device, a brake-setting appliance actuated by said time controlled device after the lapse of a predeterminedinterval of time, a normally closed circuit for simultaneously energizing said warning signal and said time controlled device, and traffic controlled means partly on the vehicle and partly along the track for controlling said circuit.

42. In anautomatic train control system,

V thecombination with a vehicle and a track therefor,.of several sources of signaling current on the track varying distinctively in their electrical characteristics and adapted to be combined, means partly on the track .and partly on the vehicle and iniuenced by the presence of other trains ahead for supplying to the vehicle at substantially all `points in its travel variable combinations of said signaling currents dependent upon the number of intervals of distance between said vehicle and the next ltrain ahead, and automatic train lcontrol apparatus on said lvehicle selectively responsive to the varying combinations of said signaling currents for imposing different fixed speed limit for each of said current combinations.

43. In an automatic train control s stein -the combination with a vehicle, of a circuit iiation of current Yin said circuit, and means :along thev trackway responsive to the pres- Yence of a train-on the track for supplying such varying currents to the circuit -cii a passing vehicle at substantially all points in the travel of the vehicle.

544C. In an automatic train control system,

the combinationwith a vehicle, of automatic train control apparatus thereon including a circuit, electro-respoiisive means included in said circuit, said apparatus being adapted to enforce different speed restrictions for the vehicle in accordance with variations in the electrical characteristics of the current flowing in said circuit, sources ol' current along the track of different electrical characteristics and adapted to be combined, impulse means along the track divided into sections, impulse receiving means on the vehicle, each section oi said impulse means along the track when energized from said sources ot current being adapted to cooperate with said receiving means on the vehicle and produce current flowing in said circuit corresponding to the currents vapplied to that section, and means responsive to the presence of a train on the track for connecting said sources of current to a plurality of said sections in the rear of that train in progressively varied combinations, whereby the speed of the following vehicle is automatically reduced step by step as it approaches a train ahead.

45. In an automatic train control system, the combination with a vehicle, of automatic train control apparatus therefor adapted to be inliuenced to automatically enforce three or more continuing speed limitations for the vehiclei/'arying from a maximum to a minimum, and means including normally closed track circuits and stationary trackway impulse transmitting devices controlled thereby for influencing said train control apparatus and causing it to impose successively lower speed limitations at intervals along the track as the vehicle approaches an occupied track circuit.

46. In an automatic train control system, the combination with a vehicle, oi' automatic train control apparatus therefor adapted to be influenced to automatically enforce three or more continuing speed limitations for the vehicle varying from a maximum to a minimum, said apparatus also including a warning signal operated prior to the application of the brakes, and means including normally closed track circuits and stationary trackway impulse transmitting devices controlled thereby orintluencing said train control apparatus and causing it to impose successively lower speed limits at intervals along the track as the vehicle approaches an loccupied track circuit.

tions upon the speed ot the vehicle at said intervals along the track as the vehicle passes said impulse devices.

48. ln an automatic train control system, the combination with a rairoad track, of a plurality oi stationary impulse devices disposed al' the track at intervals in the braking distance ior vehicles traveling on the track, means responsive to the presence of a train on the track for governing the controlling conditioei of said impulse devices in accordance with traiiic conditions ahead, and automatic train control apparatus on a following vehicle adapted to enforce automatically successively lower speed limitations tor a. vehicle under the influence of said impulse devices as the vehicle passes them, said train control apparatus having a tendency to assume its lowest speed condition.

49. ln an automatic train control system, the combination with a vehicle and a track therefor provided with normally closed track circuits, of a permissive speed device on the vehicle changeable step by step to establish different continuing permissive speeds for the vehicle, a speed responsive device on the vehicle governed by the actual speed thereof, a warning signal and a brakesetting appliance on the vehicle governed jointly by said permissive speed device and said speed responsive device and operated successively with anr intervening interval of delay when the actual speed exceeds the prescribed permissive speed, and means partly on the vehicle and partly along the track and governed by said track circuits for causand establish successively lower permissive speeds as the vehicle travels through a region of limited extent behind a track circuit occupied by a train ahead, whereby lower speed limitations are automatically imposed upon said vehicle as it approaches a train ahead and the warning signal will be irst operated and then after an interval, the brakes will be automatically applied, if the speed of the following vehicle exceeds thev ,circuit` a speed governor on said vehicle for operating one of said circuit controllers, and a device on said vehicle Jfor determining` the ing said permissive speed device to change speed at which the vehicle may run, for operating the other ot said circuit controllers.

52. Automatic train control equipment for railway vehicles comprising a normally energized brake control device, a plurality of circuits corresponding to different permissive speeds for the vehicle and each elfective to maintain said brake control device energized, speed-responsive means governed by the actual speed of the vehicle for opening such ot said circuits as correspond to speeds lower than the existingv actual speed, and normally energized electro-responsive permissive speed means adapted to open and close said circuits selectively, said permissive speed means being biased toward its lowest speed condition and acting automatically to open all of said circuits when deeneroized.

53. In an automatic train control system for railway vehicles, speed control apparatus on a vehicle comprising a normally energized brake setting device, a normally closed energizing circuit for said device having a plurality of branches in multiple, speed-responsive means tor selectively controlling said multiple branches in accordance with tie actual speed of the vehicle, electro-responsive permissive speed means for selectively controlling said multiple branches in accordance with the safe permissible speed for the vehicle, said permissive speed means being biased to open all of said branches when deenergized, and means responsive to the presence of trains on the track for distinctively enero'izing said permissive speer means to conform with the number of predetermined intervals of distance between the vehicle and a train ahead.

Y54.111 a system for protecting traliic on railroad tracks divided into blocks, the combination with speed control apparatus on a vehicle selectively responsive to electrical energy of ditl'erent characteristics and adapted to enforce corresponding limitations on the speed of the vehicle, of means partly on the vehicle and partly along the track normally supplying electrical energy to the vehicle at substantially all points in its progress through each block for controlling said apaaratus said means actin@ automaticall to vary the electrical characteristics of such energy supplied to the vehicle in a block to conform to the extent of unoccupied track in advance of the vehicle.

55. In an automatic train control system for railroads having tracks divided into track sections each provided with a normally closed track circuit, speed control apparatus on a vehicle adapted to restrict the speed thereof to any one of a plurality'of speeds, said apparatus having a tendency t0 assume its lowest speed condition, and means controlled by said track circuits and norinally acting in opposition to sc id tendency for causing said apparatus to eiiferce any one of three or more different speed restrictions conforming with the number' of track sections between said vehicle and the next vehicle ahead. Y

56. In an automatic train control system for railroads, the combination with automatic speed control apparatus on a vehicle .including means permitting tlie vehicle to proceed at a Vmaximum speed, other means permitting the vehicle to proceed at a restricted speed, and control means responsive to electrical energy of different characterist'cs for rendering one or the other of said means effective, of yimpulse transmitting means for normally supplying such electrical energy to the control means on a vehicle at substantially all points in its travel of a characteristic depe Adent upon the proxiinity of the next train ahead.

57. An automatic train control system for railroads lia-ving tracks divided into blocks, comprising traflic controlled influence coniinunicating means partly on the track and partly on a vehicle for producing on said vehicle during its progress through eacli block a clearance current of one character for maximum speed or another current of a distinctive character for a limiter speed, and train control apparatus on the vehicle biased to a. condition to retard the vehicle, said apparatus being normally influenced at sul staiitially all points in the travel of the veliicle by said currents in opp sitionvto its bias to assume a condition eni rcing speed limitL tions corresponding to the character of current supplied thereto.

58. In an automatic train control system, the coinbination'ivitli automatic speed control apparatus on a vehicle comprising a normally energized brake control device, a plurality of circuits each adapted to malintain said device energized, speed responsive means connected to the Wheels of the vehicle for opening and closing said circuits in correspondence with the actual speed of the vehicle, electro-responsive means including a movable element and contacts controlled thereby which are included in said circuits, a contact shoe .on the vehicle, a partial circuit including said electro-responsive means and terminating at said contact shoe and the Wheels of the vehicle, and traflic controlled means along the track including contact rails for energizing said electro-responsive means to a variable degree.

59. In an automatic train control system, a railroad track divided into track sections each provided With a normally closed track circuit and track relay, a contact rail associated With each track section, and a plurality of partial circuits for each contact rail including sources of current of different a railroad track divided into track sectionsA each provided With a normally closed track circuit and a track relay, an impulse device associated With eacli track section, a series of partial circuits for controlling each impulseA device governed by a plurality of the track relays belonging to the corresponding track section and a number of track sections in advance thereof, one partial circuit of each series including' the front contacts of said plurality of track relays, each of the other partial circuits of each series including a back contact of a given track relay of said plurality and front contacts of the track relays of' said plurality in the rear thereof and sources of current of different electrical characteristics incluced in said partial circuits.

61. In a speed control system for railway vehicles, in combination, a ti'ackway divided into sections each provided with a track relay, signal rails associated with said track sections, means controlled by said track relays for impressing current of a uniform voltage upon said signal rails when the trackvvay is free of vehicles and for iinpressing diiferent voltages upon a. plurality of the signal rails in the rear of a train Varying in proportion to their distance from such train.

62. In a speed control system for railway vehicles, a track divided into track sections, a signal rail associated with each track section, means responsive to the presence of a vehicle in any track section for energizing a number of the signal rails in the rear thereof With energy of different voltages, the voltage applied to a given signal rail being proportional to its distance from said vel liicle ahead, and a permissive speed device" on a following vehicle adapted to be set to a permissive speed position corresponding to the voltage of the signal raill of the track section said following vehicle is then occupying. l

63. In a speed control system for railway vel icles, a trackway divided into track sections, a. signal rail associated with each track `ection, means responsive to the presence of a vehicle in any track section for producing` train adapted to be set to a permissive speed positionv corresponding to the electrical conb that train isoccupymg;

64.' ln an automatic speed control system dition ot the sional rail of the track section for railroads, signal rails alongthe track,

means for supplying electrical energy of dili-` rail, a circuit on a vehicle receiving said electrical energy trom said signal rails, a permissive speed device on the vehicle governed by said circuit and having a movable element adapted to beset to ditlierentpositions corresponding to the character of electrical i u" in said circuit, and ieans including a speed responsive device connected to the Wl eels of the vehicle for applying the brakes of toe vehicle Whenits actual speed exceeds that prescribed by the existing position of said movable element.

(35.y ln a speed control system for railway vehicles, a track, a vehicle thereon, a permissible speed device on the vehicle having a maximum speed position and a minimum speed position and means including continuous devices along the tra-ckway for normally holding said permissible speed device in its maximum speed position. f

66. In a speed control system` "for railvray vehicles, a track, a vehicle there-on, an actual speed device on the vehicle, a permissible speed device on the vehicle khaving a maximum speed position and a minimum speed position, means including" continuons devices along the tra-ckvvay for n rnn ly holding said permissible speed device in its maximum speed position, means for reaarding the vehicle and means for actuating the retarding means When the actual speed of the vehicle exceeds a predetermined maximum speed.

6T. In a speed control system for railway vehicles, a track, vehicle thereon` a permissible speed device on the vehicle having' a maximum speed position. and a minimum speed position, means for normally holding the said permissible'speed device in its maximum speed position, means for moving the said permissible speed device from its maximum speed position toward its minimum speed position, and means including continuous devices along the track- Way for restoring the said permissible speed device to its maximum speed position.

68. ln a speed control system `for railway vehicles, a track, a vehicle thereon, an actual speed device on the vehicle, a permissible speed device on the vehicle having a maximum speed position and a mmimum speed position, means for normally holding the said permissible speed device' in its maximum speed position, means for moving the said permissiblespeed device from its max1-' mum speed position toward its minimum speed position, means including continuous `devices along the trackway for restoring the said rpermissible speed device to its maximum speed position, means for retarding the vehicle, and means for actuating the retarding means when the actual speed of the vehicle exceeds the permissible speed corresponding to the position of the permissible speed device.

G9. A safety apparatus for the automatic control of the speed of vehicles moving along a. trackivay, comprising a permissible speed device on the vehicle movable between a permissible maximum speed position under safety conditions, and a permissible minimum speed position under danger conditions, y,

means for automatically moving the permissible speed device from a maximum to and positively electrically maintaining it at any one of a plurality of submaximum positions or to a minimum position step by step or reversing such movement corresponding to the position of a temporary hazard moving along the same trackivay With respect to the vehicle carrying the device.

70.` Thecombination with a. railway divided into blocks, each equipped with roadvvefy control mechanism electrically? operated, oil a safety apparatus carried by a vehicle traveling along the railway, for theautom tic control oi the speed of such vehicle, incniding a permissible speed `device and means for moving such device to and positively electrically maintaining itV at any one of. series of rate indicating positions varying with the proximity of a temporary hazard to the moving vehicle.

7l. The combination With a railway divided into blocks, each equipped with roadway control mechanism electrically operated, of a safety apparatus carried by a vehicle traveling along the railway, Jfor the automatic control of the speed of such vehicle, including a permissible Aspeed device and means i or moving such device through electrical impulses received through the roadway mechanism to any one of a series of rate indicating positions varying With the proximity of a temporary hazard moving past the rails and depending upon the distance measured in blocks of such hazard from the z vehicle. y

72. The combination With a railway divided into blocks, each equipped with road-l ivay control mechanism electrically operated;

er" a safety apparatus carried by a vehicle traveling along the railway for the automatic control of the speed of such vehicle, including a permissible speed device actuated through electrical impulses received through the roadway mechanism', and varying by 4speed for the vehicle, means adapted to retard the vehicle whenever such established speed is exceeded, in combination with .Y means along the traclrway and electrically cont-rolled devices actuated therefrom whereby the permissible speed establishing device is automatically moved to a predetermined safe speed position by the mere presence of a temporary hazard along the traclrway at a predetermined distance from the vehicle.

74. An apparatus for the control of vehicles moving along a. traclrway comprising a. device on the vehicle movable to different positions to establish a 'variable permissible speed for the vehicle, means adapted to retard the vehicle whenever such established speed is exceeded, in combination with means along the trackway and electrically controlled devices actuated therefrom whereby the permissible speed establishing` device is automatically moved to a predetermined safe speed position by the mere presence of a temporary hazard along the trackway at a predetermined distance from the vehicle and automatically moved to a different safe speed establishing position by such presence whenever the distance of the hazard from the vehicle is varied by a definite increment.

Y 75. An apparatus for the control of vehicles moving along a traclrway, comprising a device on the vehicle -movable to different positions to establish a variable permissible speed for the vehicle, means adapted to retard the vehicle whenever such Y established speed is exceeded, in combina- -tion with means along the tracltway and electrically controlled devices on the vehicle actuated therefrom whereby the permissible speed establishing device is automatically moved to a predetermined safe speed establishing position by the mere presence of a temporary hazard. along the trachway at a predetermined distance from the vehiclefand automatically moved to a different-safe speed establishing position by ysuchpresence whenever the distance of the hazard from the vehicle is varied by a delinite increment, in combination with automatic means for restoring the permissible speed establishing devices on the vehicle to normal position when the temporary hazard is moved a predetermined dist nce from the vehicle or vanishes.

- and means controlled by the presence of a hazardin advance of the vehicle for moving the permissive speed device to and positively electrically maintaining it at any of i the "different speed positions according to the proximity of the hazard to the vehicle.

77. In apparatus of the character set forth, the combination with a vehicle, of a permissive speed device having a normal clear or safety position and movable therefrom to and maintainable at a plurality of successively lower speed positions, and means controlled by the pi'esence of a hazard in advance of the vehicle for moving the permissive speed device to and positively electrically maintaining it at any of the low er speed positions according to the proximity ofthe hazard to said vehicle.

78. In apparatus of the character set forth, the combination with a traclrway for vehicles, of a vehicle that traverses the same, a permissive speed device having a` norma-l clear or safety position and movable therefrom to and inaintainable at a plurality of successively lower speed positions, and mechanism dependent on the appearance of a temporary hazard on the .trackway and its position with relation to the vehicle to move the permissive speed device to and positively electrically maintain it at a predetermined lower speed position.

79. In apparatus of the character set forth, the combination with a trackway for vehicles, of a vehicle that traverses the same, a permissive speed device having a normal clear or safety position and movable there-- from to and maintainable at a plurality of successively lower speed positions, and mechanism dependent on the appearance of a temporary hazard on the trackway and its position with -relation to the vehicle tofvehicles, of a. vehicle that traveises thesame, a permissive speed device having a normal clear or safety position and movable therefrom to and positively1 electrically maintainable at a plurality of successively lower speed positions, and mechanism dependent upon tlie appearance of a temporary hazard on the trackway to intermittently move the permissive speed device to different speed positions as the vehicle and hazard relatively approach each other.

8l. In apparatus of the character set forth, the combination with a traclrway divided into sections, of a vehicle adapted to pass along the traclrway, a permissive vspeed device movable to different speed positions, and track-side mechanism automatically controlled by the relative approach of a hazard and the vehicle through successive track sections to cause the permissive speed device to change to a different position upon the change of the number of track sections between the vehicle and hazard and maintain said permissive speed device in substantially a predetermined positionwhile the vehicle is in one section.

82. In apparatus of the character set iorth, the combination with a trackway divided into sections, of a vehicle adapted to pass along the trackway, a permissive speed device movable to different speed positions, and trackside mechanism automatically controlled by the appearance of a hazard in a section in advance of the vehicle to cause said permissive speed device to change successively to different predetermined positions as the vehicle successively passes into diiiferent track sections and more closely approaches the hazard, while maintaining the permissive speed device in substantially said respective predetermined positions while in said track sections.

83. In apparatus of the character set forth, the combination with a trackway divided into sections, or a vehicle adapted to pass along the trackway, a permissive speed device movable to different speed positions, and trackside mechanism automatically controlled by the appearance of a hazard in a section in advance of the vehicle to cause said permissive speed device to change successively to different predetermined lower speed positions as the vehicle successively passes into different track sections and more closely approaches the hazard while maintaining the permissive speed device in a substantially iixed position while in a section, said means returning the permissive speed device reversely to different higher speed positions upon the relative separation of the hazard and vehicle by an increasing number of sections.

84. In apparatus of the character set forth, the combination with a vehicle, of means for indicating danger and also a pluT rality of safe rates of speed for said vehicle under different conditions, and means dependent upon the appearance of a temporary hazard in advance of the vehicle for automatically causing the said means to indicate danger or any of the said safe rates of speed according to the distance between the hazard and the vehicle, maintaining the proper indication while a predetermined distance remains substantially the same, and changed to another indication when a ditterent predetermined distance obtains.

85. In apparatus of the character set tortl, the combination with a vehicle, of means for indicating a maximum safety rate of speed, a danger condition and a plurality ot' intermediate sub-maximum speeds, and means for causing said indicating means to normally indicate the maximum safety rate of speed including controlling mechanism dependent upon the appearance of a temporary hazard in advance of the vehicle for automatically causing the said means to indicate a danger or any of the intermediate rates of speed according to the distance between the vehicle and the hazard.

86. In apparatus of the character set forth, the combination with a vehicle, of means for establishing a maximum sate speed under clear conditions, a minimum safe speed under danger conditions, and a pluraity of safe speeds between the two, and means dependent on the appearance of a hazard and the disance'between the same and the vehicle for effecting the operation of said means to establish and temporarily positively electrically maintain one of said predetermined sate speeds for the vehicle.

87. In apparatus of the character set forth, the combination with a vehicle, of means for establishing a maximum safe speed under clear conditions, a minimum safe speed under danger conditions, and a plurality of safe speeds between the two, and means dependent on the appearance of a hazard and the distance between the same and the vehicle for effecting the operation of said means to establish and temporarily positively electrically maintain one of said predetermined safe speeds for the vehicle, and to alter said established speed to another speed when a predetermined change takes place in the `distance between the vehicle and hazard.

88. A safety apparatus for the automatic control of the speed of a vehicle moving along a trackway divided into blocks comprising a highway control including a plurality of series of control devices each adapted to be employed in the indication of a permissible speed for the vehicle corresponding to the presence of a temporary hazard in 4a block a distance from the vehicle predetermined witli respect to the actuation oi each series of control devices.

89. A safety apparatus for the automatic control of the speed of a vehicle moving along a trackway divided into blocks comprising a highway control including a plus rality of series of control devices each adapted to be employed in the indication of a permissible speed for the vehicle corresponding to the presence of a temporary hazard in a block a distance from the vehicle predetermined with respect to the actuation of each series of control devices, and which distance is different for each series.

90. In an automatic train control system for protecting tratlic on railroads, a vehicle and automatic brake control apparatus thereon operable under different controlling influences to establish any one of a plurality of different speed limits in accordance with the influence then being communicated to the vehicle, said apparatus automatically applying the brakes of the vehicle if its running speed at any time exceeds the speed limit When in effect, iniiuence receiving means on the vehicle, an alternating current transmission line along the track, and @5 means along the track energized from said transmission line and responsive to the presence of trains for co-operating With said vehicle carried influence receiving means to communicate to the vehicle at substantially 19 all points in its travel some one of said controlling influences dependent upon the eX- tent of unoccupied track in advance ot the vehicle.

91. In an automatic train control system 1,5 for railroads, an alternating current transmission line along the track, means along the track energized from said line for supplying alternating current at intervals along the track to partial circuits including a track 2U rail, said .means being responsive to the presence of trains on the track to vary the controlling characteristics of the current in each partial circuit dependent upon the proximity of a train ahead, influence receiv- 25 ing means on the vehicle continuously responsive to the controlling characteristics of the current supplied to the partial circuit at the point Where the vehicle is then located, and brake control apparatus on the vehicle responsive to said controlling characteristics to establish any one of a plurality of different speed limits which the vehicle cannot exceed Without an automatic application of its brakes.

92. In a train control system for railroads, the combination with a vehicle, automatic brake control apparatus on the vehicle including a speed responsive device driven from the Wheels thereof, said apparatusbeing changeable to establish a maximum speed limit and a plurality of lower fixed speed limits which the vehicle cannot eX- ceed Without an automatic application of its brakes, means along the track provid ing a series of partial circuits each extending for a limited distance along the track, track circuit controlled means for energizing said partial circuits with alternating current of different controlling characteristics dependent upon the extent of unoccupied track ahead, and impulse receiving means on the vehicle continuously responsive to the energization of said partial circuits for governing said brakel control apparatus.

VVINTHROP K. HOVVE. 

